In an automatic transmission for an automotive vehicle, a fluid coupling or torque converter is located between the input shaft from the vehicle engine and the transmission input shaft, and vibrations which normally occur in the drive train are effectively absorbed hydraulically in the fluid coupling. However, a hydraulic torque converter has a certain degree of slippage, even at high speeds, so as to lose fuel economy. To enhance fuel economy of a vehicle equipped with an automatic transmission, a lock-up clutch may be incorporated in the torque converter which, at a predetermined point relative to vehicle speed, load and acceleration, engages to provide a direct drive between the input and output of the torque converter in high gear.
When locked in direct drive, the torsional vibrations in the drive train will not be hydraulically absorbed and a torsional vibration damper is required. As the space requirements for a torque converter are limited, the present invention relates to a compact vibration damper assembly which is positioned in the torque converter housing along with the lock-up clutch so as to absorb the drive train vibrations.